Mobile Nation

For most of the way between Palm Springs and Phoenix, Interstate 10 cuts a straight line through the desert; a brick on the accelerator could drive it. Most people don't find too many reasons to stop, except maybe to fill the gas tank or the stomach. The landscape is relentlessly rocky and beige, except for the green valley at Blythe, where the last remnants of the Colorado River are siphoned off to irrigate alfalfa, cotton and other crops that should not grow in a place this dry and harsh.

Seventeen miles beyond Blythe and the Arizona border, towering signs for gas stations and fast food joints hint at a middle-of-nowhere stopping point, the kind of one-dimensional town that wants you to spend your money and get back on the road as quickly as possible. But as you come closer, you notice a sprawling community that should have no reason to exist beyond the standard few blocks clustered just off the interstate. Specks of white twinkle in the desert like little pockets of misplaced snow. Each one is a fiberglass rooftop belonging to one of the thousands upon thousands of recreational vehicles that briefly turn this stretch of desert into a booming urban center.